Hydrogenated n and p doped Czochralski Si substrates have been studied by means of atomic force
microscopy, scanning and transmission electron microscopy, Raman spectroscopy and microwave
photoconductivity decay techniques. The measurements show that the surface is roughest in ndoped
samples which are plasma treated at high frequency. The cone density was found to be
highest on p-doped samples, which correlates well to the higher density of defects observed in pdoped
samples. The surface cones were found to consist of nanograins, twins and stacking faults
with random orientations, several hydrogen induced defects and bubbles. The size, density and
formation depth of the subsurface defects were seen to depend on doping type, doping level, plasma
frequency and hydrogenation time. Raman spectroscopy shows formation of nearly free hydrogen
molecules, which are presumed to be located in nano-voids or platelets. These molecules dissolved
at temperatures around 600°C. By means of the &-PCD measurements, it is demonstrated that
hydrogen-initiated structural defects act as active recombination centres, which are responsible for
the degradation of the minority carrier lifetime.